This disclosure relates generally to social networking systems, and in particular to ways of incorporating content items previously delivered, but not viewed, to users of a social networking system into new content feeds.
Social networking systems allow users to connect to and communicate with other users of the social networking system. Users create profiles on a social networking system that are tied to their identities and include information about the users, such as interests and demographic information. The users may be individuals or entities such as corporations or charities. Because of the increasing popularity of social networking systems and the significant amount of user-specific information maintained by social networking systems, a social networking system allows users to easily communicate information about themselves to other users. For example, the social networking system generates stories describing actions performed by social networking system users and presents the stories to other social networking system users. However, not all stories delivered to a device associated a user are actually presented to the user. Additionally, this missed content may have more value to the user than other more current stories in subsequent content feeds.